Determining maximum cutting torch tip size based on acetylene bottle size?

[toukow]

I'm hoping you guys can straighten me out. Can you tell me how I'm misapplying the documents at the links? I have attached excerpts from the Miller data (all white documents) at the links, as well as additional Victor tip data (documents with green) . My goal is simply to have the maximum range of tips on hand for cutting, without exceeding the bottle size flow limit.

I found the maximum allowable flow rate in the first Miller document, which is simply applying the 1/7 rule for acetylene flow based on tank size. I have 75 cubic foot tank, so 10.7 SCFH is the limit. I know the new standards are now based on 1/10 of rated capacity for intermittent use. This also shows the tip range for this tank size to be 12-00/12-4.

I found the flow rates for the Miller tips shown above, in particular the 12-3 & 12-4 tips, in the second excerpt. My confusion is that when I look at this tip specification flow rates for the 12-3 and 12-4 tips, it shows a flow rate which exceeds the maximum flow rate for a 75-cu ft tank.

I have also attached excerpts for the Victor tips including the heating tips. In examining data from Victor, it seemed like a number #1 cutting tip made the most sense, given the #2 tip starts out with its flow equal to the maximum flow rate for my tank. My LWS is saying I can use the #2, but they did not really research the details when replying.

1. What am I missing in interpreting the Miller data? Are these maximum values for flow rates for the respective Miller tips? Still don't see how a #4 will work.
3. Does the #1 tip from the Victor data make sense to buy? Or can this bottle size support a #2 tip, given I appear to be missing something here?
5. I'm thinking of buying the MFA-1, Size 4 heating tip as well. I've read that fuel supply to heating tips can be an issue, but infer this tank can support such a flow rate.

Thanks for your time, Toukow

https://www.millerwelds.com/-/media...xy-fuel/fuelgascylinderrequirements.pdf?la=en

https://equiptoweld.millerwelds.com...ding_Brazing_HeatingTip_FlowPressure_Data.pdf

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[Tractor Seabee]

For flame cutting #1 and smaller tips will do 95% of what the normal person does. I keep a #0 in my torch and have 000-2 available. The #2 has never been used. Most folks use a lot larger tip than needed. Bigger is not better. Those charts are handy though. I have done thousands of cuts on 1/4" stock and schd 40 pipe with a #0. Bigger tips just make a wide messy cut with a lot of slag. If the edges of you cut are melted rounded you tip is too big. Your 75CF tank can handle up to #1 with no problem. Heating is different, a wide open #6 will suck the acetone out with the acetylene. I have had it happen, snuffs out the flame. Stay with #4 or smaller, better to use propane instead if you need more heat. Acetylene regulator and tips work fine, tank valve is the same. Heavy propane use will destroy you hose though. There is a hose that will work on both. This is all based on experience not the charts.

Ron

 

[dragoneggs]

I was hoping Ron would jump in... in fact I was going to PM him about this thread.

Sure do miss ShieldArc. Ron are you staying in touch?

 

[jaxs]

I do it pretty much like Seabee. A #00 stay's in my cutting torch 80% of time,#000 and #1 on the cart and all others sitting on a shelf unused for longer than I recall. I use oxy-propane for cutting, heating,brazing,soldering and oxy-acety for fuel welding and critical brazing. 2 piece cutting tips work better for me so I always use them with propane.

 

[toukow]

Thanks everyone. I bought this setup 14 years ago, and hadn't reviewed the manual for a long time. The issue of acetone withdrawal was forgotten, so glad I read some threads on the matter. I will buy the #1 tip then, and perhaps something smaller than the #0 I currently own per Seabee's comments.

I tend to buy tools so I have them if ever needed, instead of mickey mousing something on the fly (yeah, I waste plenty of $$). Is the heating tip used that much, I assume usually for preheating? Is it that much better for preheating than just using the cutting torch without the additional oxygen? Or am I misapplying the tool by doing so, though I'm not seeing the risk.

Thanks for the education, Toukow

 

[yomax4]

I recommend the Victor chart. But I don't own Smith. In my 1" and thinner cutting I never go higher than 7 on Acet. 20-25 on O2. I have #2 &3 tips but use 00 and 0 90% of the time. Smith mixes in the tip so everything is a little different with them. I remember in my distributor days the scrappers would come in and ask for #3 & 4 cutting tips. They say they can cut faster. What they didn't understand was gas consumption. They used 3X more gas than needed and really didn't cut that much faster. Your LWS has free cut charts for Acetylene, Alternate fuels and Automation if you ask for them. Most people are surprised what they show. For heating tips there are really no options with the knee high and smaller acetylene tanks. If you push it you will get acetone in your regs,hose and torch and gum everything up. The cut charts show heating tips as well. You can heat to a certain degree with your cutting tip if you have small tanks. When heating and cutting I use Alternate fuels ( propane, chemolene, propylene, MAPP etc ) as much as possible. They are much more stable but there is a learning curve lighting them out in the wind.

 

[Rebeldad1]

Did a lot of torch work in the shipyards and for a marine construction company.
used basically 4 sizes.
#s 00 and 0 for lighter weight materials
#1 (most of the time) for up to 1 inch plate.
#2 for cutting construction waste and equipment up for scrap

These sizes are pretty much the same if using natural gas or propane though its a lower temperature gas.
Also takes different tips.

Used propane for most everything at home. Way cheaper...

 

[jaxs]

Snip:checkmark:
I tend to buy tools so I have them if ever needed, instead of mickey mousing something on the fly (yeah, I waste plenty of $$). Is the heating tip used that much, I assume usually for preheating? Is it that much better for preheating than just using the cutting torch without the additional oxygen? Or am I misapplying the tool by doing so, though I'm not seeing the risk.

Thanks for the education, Toukow

For heating to bend or forge I use a propane grill bottle , 1 Benzomatic Trigger Start Camp Torch,and a second Benzomatic torch knob adjustable flame,manual light with orfice drilled oversize and larger mixing chamber for weedburner size flame. Much quicker to light up, use and cheaper than oxy-fuel. For videos on large homemade propane heating torchs,search "how to build a forge".

 

[toukow]

I recommend the Victor chart................. If you push it you will get acetone in your regs,hose and torch and gum everything up.

Did a lot of torch work in the shipyards and for a marine construction company.
used basically 4 sizes.
#s 00 and 0 for lighter weight materials
#1 (most of the time) for up to 1 inch plate.

These tanks are interesting from a design standpoint, and I'm glad I read the warnings about excessive draw. Never knew about the acetone liquid so what you don't know CAN hurt you. So if I'm reading the chart correctly for the Victor tips which I've included in the original posts, the #1 sized tip will at :

3 PSI will cut 1/2" at 8 SCFH
5 PSI will cut 3/4" BUT will exceed the tank rating of 10.7 SCFH at 13 SCFH

If the flow rate is linear, then I'm limited to about 5/8" steel for continuous use. Is that a correct interpretation? Thanks, Toukow

 

[BukitCase]

All your concerns are EXACTLY why my acetylene tank is a size 5 (330 Cu.Ft.) - I went thru all the crap you are til I realized that once you pay the extra for the larger tank, it doesn't cost you any more to let a big tank sit til you need it, than a smaller one. (That is, if your LWS will "SELL" you tanks - I have 6 or 7 "owner" tanks, have had the O/A tanks since 1979.)

At the time I got the big tanks I needed a rosebud; at that time, the SMALLEST rosebud available for my Victor torch would just barely work with the 330 CF tank. They now offer a couple smaller ones; don't recall size #'s.

The bigger tank has sat there not costing me anything for up to 10 years, still worked fine - finally used it up a couple years ago, refilled and it may sit there for a week or ANOTHER 10 years. With as many tanks as I have, yearly rentals would've cost me about $12,000 by now - IMO, if you plan on having the O/A around long term you should ask your LWS about owner tanks and just "cry ONCE" - I did; my tank cart sits chained to a wall in an open air (but covered) work area with a barbeque cover over it til I need it.

Caveat; you won't get away with the big bottles on a HF weld cart, they won't fit and that's a GOOD thing (they ain't LIGHT ) ... Steve